#1261 Restore Windows 7 compatibility for most parts of ReaLearn

Helgobox App and the egui-based GUIs of the plug-in are still not Windows-7-compatible!

.github/workflows/release.yml

@@ -15,7 +15,7 @@ jobs:
         include:
           - artifact: windows-x86_64
             os: windows-latest
-            toolchain-suffix: x86_64-pc-windows-msvc
+            toolchain: 1.77.2-x86_64-pc-windows-msvc
             lib-file-name: helgobox.dll
             extension-file-name: reaper_helgobox.dll
             target: x86_64-pc-windows-msvc
@@ -24,7 +24,7 @@ jobs:
             features: "playtime,egui,licensing"
           - artifact: windows-i686
             os: windows-latest
-            toolchain-suffix: i686-pc-windows-msvc
+            toolchain: 1.81.0-i686-pc-windows-msvc
             lib-file-name: helgobox.dll
             extension-file-name: reaper_helgobox.dll
             target: i686-pc-windows-msvc
@@ -33,48 +33,48 @@ jobs:
             features: "egui"
           - artifact: macos-x86_64
             os: macos-latest
-            toolchain-suffix: x86_64-apple-darwin
+            toolchain: 1.81.0-x86_64-apple-darwin
             lib-file-name: libhelgobox.dylib
             extension-file-name: libreaper_helgobox.dylib
             target: x86_64-apple-darwin
             use-cross: false
-            profile: release
+            profile: release-strip
             features: "playtime,egui,licensing"
           - artifact: macos-aarch64
             os: macos-latest
-            toolchain-suffix: x86_64-apple-darwin
+            toolchain: 1.81.0-x86_64-apple-darwin
             lib-file-name: libhelgobox.dylib
             extension-file-name: libreaper_helgobox.dylib
             target: aarch64-apple-darwin
             use-cross: false
-            profile: release
+            profile: release-strip
             features: "playtime,egui,licensing"
           - artifact: linux-x86_64
             os: ubuntu-20.04
-            toolchain-suffix: x86_64-unknown-linux-gnu
+            toolchain: 1.81.0-x86_64-unknown-linux-gnu
             lib-file-name: libhelgobox.so
             extension-file-name: "not-yet-supported"
             target: x86_64-unknown-linux-gnu
             use-cross: false
-            profile: release
+            profile: release-strip
             features: ""
     #          - artifact: linux-aarch64
     #            os: ubuntu-22.04
-    #            toolchain-suffix: x86_64-unknown-linux-gnu
+    #            toolchain: 1.81.0-x86_64-unknown-linux-gnu
     #            lib-file-name: libhelgobox.so
     #            extension-file-name: ""
     #            target: aarch64-unknown-linux-gnu
     #            use-cross: true
-    #            profile: release
+    #            profile: release-strip
     #            features: ""
     #          - artifact: linux-armv7
     #            os: ubuntu-22.04
-    #            toolchain-suffix: x86_64-unknown-linux-gnu
+    #            toolchain: 1.81.0-x86_64-unknown-linux-gnu
     #            lib-file-name: libhelgobox.so
     #            extension-file-name: ""
     #            target: armv7-unknown-linux-gnueabihf
     #            use-cross: true
-    #            profile: release
+    #            profile: release-strip
     #            features: ""
     env:
       # This is relevant for macOS builds only (and only if not overridden).
@@ -96,7 +96,7 @@ jobs:
         uses: actions-rs/toolchain@v1
         with:
           profile: minimal
-          toolchain: 1.81.0-${{ matrix.toolchain-suffix }}
+          toolchain: ${{ matrix.toolchain }}
           target: ${{ matrix.target }}
           override: true
       # Install OS dependencies (Linux/macOS only)

.github/workflows/windows-i686.yml

@@ -31,7 +31,7 @@ jobs:
       - uses: actions-rs/toolchain@v1
         with:
           profile: minimal
-          toolchain: 1.81.0-i686-pc-windows-msvc
+          toolchain: 1.77.2-i686-pc-windows-msvc
           target: i686-pc-windows-msvc
           override: true
       - name: cargo build

.github/workflows/windows-x86_64.yml

@@ -31,7 +31,7 @@ jobs:
       - uses: actions-rs/toolchain@v1
         with:
           profile: minimal
-          toolchain: 1.81.0
+          toolchain: 1.77.2
           override: true
       - name: cargo check
         uses: actions-rs/cargo@v1
@@ -57,7 +57,7 @@ jobs:
       - uses: actions-rs/toolchain@v1
         with:
           profile: minimal
-          toolchain: 1.81.0
+          toolchain: 1.77.2
           override: true
       - name: cargo build
         uses: actions-rs/cargo@v1

CONTRIBUTING.adoc

@@ -134,7 +134,7 @@ On Windows, it's necessary to use the MSVC (Microsoft Visual Studio C++) toolcha
 +
 [source,shell]
 ----
-rustup default 1.81.0-x86_64-pc-windows-msvc
+rustup default 1.77.2-x86_64-pc-windows-msvc
 ----
 . Download and install https://git-scm.com/download/win[Git for Windows]
 . Clone the ReaLearn Git repository

Cargo.toml

@@ -126,9 +126,22 @@ cached = "0.53.1"
 imageproc = "0.25.0"
 
 [profile.release]
-# There's a long reasoning about those values in CONTRIBUTING.adoc
 debug = 2
-# Switching to "symbols" will reduce size even more but leads to useless stack traces when panicking
+
+[profile.release-strip]
+inherits = "release"
+# We use this profile on Linux and macOS only. On Windows, we build with older Rust version 1.77.2
+# in order to support Windows 7. This old version strips away too much due to an implementation
+# error in rustc:
+#
+#     "Prior to 1.79, this unintentionally disabled the generation of *.pdb files on MSVC, resulting
+#     in the absence of symbols."
+#     (https://doc.rust-lang.org/rustc/codegen-options/index.html#strip).
+#
+# Not stripping on Windows is okay because the PDB is a separate file anyway. We do the following
+# mainly for macOS. There's a long reasoning about the concrete values in CONTRIBUTING.adoc.
+# BTW, switching to "symbols" would reduce size even more but leads to useless stack traces when
+# panicking.
 strip = "debuginfo"
 split-debuginfo = "packed"
 

main/Cargo.toml

@@ -5,7 +5,7 @@ authors = ["Benjamin Klum <[email protected]>"]
 edition = "2021"
 build = "build.rs"
 license = "GPL-3.0"
-rust-version = "1.81.0"
+rust-version = "1.77.2"
 publish = false
 
 [features]

main/src/domain/backbone.rs

@@ -24,13 +24,15 @@ use helgobox_api::persistence::{
 };
 use imageproc::definitions::{HasBlack, HasWhite};
 use once_cell::sync::Lazy;
+// Use once_cell::sync::Lazy instead of std::sync::LazyLock in order to be able to build with Rust 1.77.2 (to stay Win7-compatible)
+use once_cell::sync::Lazy as LazyLock;
 use palette::IntoColor;
 use reaper_high::{Fx, Reaper};
 use std::cell::{Cell, Ref, RefCell, RefMut};
 use std::cmp::min;
 use std::hash::Hash;
 use std::rc::Rc;
-use std::sync::{LazyLock, RwLock};
+use std::sync::RwLock;
 use std::time::{Duration, Instant};
 use streamdeck::StreamDeck;
 use strum::EnumCount;